#include <iostream>
using std::cout;
using std::endl;

class Base
{
public:
    virtual void display();
};

void Base::display(){
    cout << "Base::display()" << endl;
}

class Derived
: public Base
{
public: 
    void display(){
        cout << "Derived::display()" << endl;
    }
};

void test0(){
    Derived d1;
    Base * p = &d1;
    p->display();
}

int main(void){
    test0();
    return 0;
}
